Javier Mascherano is sidelined for up to six weeks and the Argentine's absence could cause real harm to the Catalans' hopes of winning the Champions League this season

COMMENTBy Ben Hayward | Spanish Football Writer

Barcelona may well win the battle, but the Catalans might not win the war. Tito Vilanova's team twice led in Paris on Tuesday before being pegged back on both occasions by a resilient Paris Saint-Germain side, but heading home to Barcelona with two away goals remains a positive result and, given their remarkable record at Camp Nou, the Catalans will still be expected to advance. After that, though, things could get difficult.

Barca lost Lionel Messi to injury at the Parc des Princes. The four-time Ballon d'Or winner gave his side a first-half lead when he latched onto Dani Alves' wonderful defence-splitting pass and drove an angled shot past Salvatore Sirigu. But it turned out to be his last meaningful contribution as he ended the half with a hamstring problem which could see him sidelined for up to three weeks.

Messi had surprisingly started on Saturday at Celta Vigo after Argentina's gruelling trip to Bolivia in a World Cup 2014 qualifier at altitude just days earlier. That long journey, plus the extreme exertion of playing in the rarefied air of La Paz, now look to have taken their toll on the fitness of their star man.

MESSI SHOULD RETURN FOR SEMIS

Lionel Messi hardly ever gets injured these days, but his batteries were running low after the recent World Cup qualifier in Bolivia, when he was ill at half-time and later complained of the 'terrible' toll of having to play football at high altitude, some 3,600 metres above sea level.

On top of that was the long journey back to Europe and Messi perhaps paid the price for all of that as he limped off on Tuesday.

Barcelona will undergo tests on Wednesday, but Leo's impressive powers of recovery mean he is likely to return before schedule (recovery time is estimated at three weeks) and be back in time for the Champions League semi-finals, the first of which will take place on April 23rd.

Yet missing Messi will be the least of Barca's worries after another Argentine, Javier Mascherano, was stretchered off on Tuesday with ligament damage in his right knee, which will keep him out for around six weeks. Perhaps also feeling the effects of the trip to Bolivia with his national side, Mascherano (who is suspended for the second leg against PSG anyway) is set to miss the bulk of the big games ahead in the remainder of this season, as Barcelona's defensive troubles return at the worst possible time.

Captain Carles Puyol is already sidelined after knee surgery and will be out for at least another month, while Adriano is laid low with a hamstring problem. Eric Abidal was called up on Saturday for the first time since his liver transplant last year and it remains to be seen whether the Blaugrana will want to throw the Frenchman in at the deep end following his long period of recuperation.

The Catalans will now hope nothing happens to Gerard Pique, who will likely be rested this weekend against Mallorca in preparation for the second leg against PSG next week. Which player will start alongside him at Camp Nou, however, is unclear.

Marc Bartra, a late substitution against PSG on Tuesday, is one option, while Alex Song could also find himself called into action in a position in which he has never looked entirely comfortable, but for which he was signed as cover in the summer.

Indeed, Barcelona's gamble of not signing a specialist back then could come back to haunt them. The Catalans carefully negotiated a defensive crisis early in the campaign as Pique and Puyol both missed matches in the opening weeks and others stood in. Something similar is now needed, yet the Barca back line is likely to face its toughest test if the team advances to the semi-finals next week. At home and with plenty of the ball, even without Messi, Barca should survive the battle with PSG. But with a patched-up rearguard missing Mascherano and Puyol, plus top teams like Real Madrid and Bayern Munich likely to be waiting in the wings at the semi-final stage, winning the war will be a much more difficult proposition.